...... Boost controller.
Question:
- Do you know how a wastegate works?
Allow me to explain this to you. The wastegate opens, via an arm attatched to a diaphragm actuator, at a certain boost pressure to bleed off exhaust pressure. In doing so, this limits the amount of boost being expelled by the turbo.
If you were to keep the WG shut, the turbo would continue to spin faster and faster, creating more and more boost until one or more engine components gave up.
Get a manual boost controller, and......yeah.